Fuji Acros 100 and Contrast Filters

NedL · Mar 13, 2016

Gerald C Koch said:
Hi Doremus,

There is, as you say, also a red component to the general problem. But the OP question centered around darkening skies. The cited film suggests using a yellow filter to achieve this not a red one.

Sorry but I stand firm orthopanchromatic is a made up term. It was dreamed up to explain faulty sensitization of Efke films some years ago toward the red end of the spectrum to make a problem seem a feature. (As I pointed out these sensitization dyes are hard to synthesis and thus expensive. The bottom line triumphs over quality.) Find the term in Haist and I will give the matter another thought. Unfortunately marketing departments now write documentation not scientists. Does the term say anything meaningful? Is the film more ortho than panchromatic or vice versa? We don't know. Looking at the sensitivity curve Acros could just as well be called "isopanchromatic" having reduced blue sensitivity and higher yellow.

Jerry

Good point. "Isopanchromatic" actually seems to describe what I like about this film better. I like to use it without a filter, and it reminds me of using a light yellow filter with other films, but with more "separation" between different shades of green. By the way, the term "orthopan" has been bandied about by Adox with regard to their CHS II and if you look at the sensitivity curves it is also "isopan" ( if it had been just flat w/ reduced red, I would not have bought any, it's the reduced blue + increased yellow/green that makes these films attractive to me )

Old-N-Feeble · Mar 13, 2016

So should we now adopt "isopanchromatic" as appropriate terminology? That's not 'official' either... but perhaps more accurate.

JDW22 · Mar 13, 2016

Thanks all for you informative comments and suggestions. They have been most helpful. The side discussion of terminology is too much in the weeds for a nimrod like myself.

LJH · Mar 13, 2016

Leaving the discussion on wording behind for a moment (although I am confused by the notion that "orthopanchromatic" is a "made up term; aren't all terms made up?), was any consensus arrived at as to which filter colour darkens blue skies the most with Across?

Gerald C Koch · Mar 13, 2016

ic-racer said:
There is no single word to describe the spectral sensitivity; please refer to the graph in the film's datasheet.

+1 Which is what every serious photographer needs to do. Learn how to read the graph and what it implies. Also learning to interpret what filter factors mean for a specific film.

Gerald C Koch · Mar 13, 2016

LJH said:
Leaving the discussion on wording behind for a moment (although I am confused by the notion that "orthopanchromatic" is a "made up term; aren't all terms made up?), was any consensus arrived at as to which filter colour darkens blue skies the most with Across?

Well in a sense all words are made up starting with Grok the caveman saying "ouch" when he burns himself. However orthochromatic, isochromatic and panchromatic have precise meaning that people in photography understand. When, for example, someone reads the word orthochromatic it should immediately bring to mind a specific type of sensitivity curve. Shoving two of these terms together makes no sense something like saying the soup is "hotcold." The soup can't be both at the same time.

The film at the beginning of the thread recommends using a yellow filter rather than a red one for darkening the sky. With Acros you are not going to get dramatic black skies and white clouds. The film appears to be designed to produce a more natural tonal rendition closer to what the human eye sees.

LJH · Mar 13, 2016

Chilli soup out of the fridge is hotcold. Pretty sure all would agree with that, so your simile does not pass muster.

I have no issue with "orthopanchromatic", and I would guess that the majority of B&W shooters don't, either, as it is simply an evocative term - it conveys roughly what the film does in one word. You could wax lyrical for ages to convey the same notion, but, before you know it, everyone has walked away, bored, to get more claret and canapés and you're left talking to yourself. Ah, the lonely domain of the priggishly correct...

Maybe you should consider going from an orthodox acceptance of the term to a more orthopandox acceptance?

NedL · Mar 13, 2016

Gerald C Koch said:
+1 Which is what every serious photographer needs to do. Learn how to read the graph and what it implies. Also learning to interpret what filter factors mean for a specific film.

Yes. The shape of the graph, then try for yourself and see how you like it. It was not the term "orthopan" that made me go and look at the CHS II graph, it was Mirko writing about decreased blue + increased green for more "natural" rendition.

Fuji Acros 100 and Contrast Filters

Privacy & Transparency

Privacy & Transparency